Synthesis And Application Of Fluorescence Probe For Metal Ion Based On Schiff Base

In recent years,fluorescence probe imaging technology is becoming more and more popular,and the use of fluorescence analysis has become an effective method to detect heavy metal ions.In this paper,we synthesize 5 fluorescent probes based on coumarin and 2fluorescence probes based on 2-hydroxy-1-naphthaldehyde,and discuss the sensing performance and recognition mechanism of these probes.In chapter 2,fluorescent probes based on 7-diethylamino-3-acetylcoumarin were designed and synthesized.In anhydrous acetonitrile,the probe produces bright fluorescence due to the chelation of Cu²⁺with the probe;in acetonitrile aqueous solution,Cu²⁺promotes the cyclization of the probe.In addition,the probe is used for cell imaging.The other is a fluorescent probe that has a highly sensitive response to Zn²⁺.In the anhydrous methanol,the addition of Zn²⁺immediately responds to strong fluorescence.In chapter 3,we design and develop two structural transformation modes based on coumarin hydrazine derivatives.An arylhydrazono-containing coumarin derivative?1?can undergo chemical conversions in two modes.Both 2 and 3 were characterized by single-crystal X-ray diffraction.In chapter 4,fluorescence probes based on 2-hydroxy-1-naphthalene aldehyde were designed and synthesized.The probe alone is almost non-fluorescent due to the isomerization of C?28?N in the excited state.The addition of Cd²⁺can cause an immediate strong green fluorescence.Furthermore,NT gives a delayed turn-on fluorescence response to Cu²⁺,which was thanks to the inhibition of the electron transfer between excited fluorophore and paramagnetic Cu²⁺by sulfur donor.The second probe itself is non-fluorescent and produces bright cyan fluorescence upon addition of Al³⁺.The probe is complexed with Al³⁺in a 2:1coordination mode with good selectivity and anti-interference ability.In chapter 5,fluorescent probes based on coumarin derivatives were designed and synthesized.The coordination of the sulfur atom inhibits the electron transfer from coumarin to copper ions.Through the control experiment,the similarity of the probes were used to confirm the binding mode between the probe and Cu²⁺and the coordination of the sulfur atom to protect the fluorescence quenching.